Resolved single-carbon resonances in natural-abundance carbon-13 nuclear magnetic resonance spectra of proteins and glycoproteins will be used in the following projects: (1) Further studies of the region of intermolecular contact in the self-association of hen egg-white lysozyme. (2) Conformation in solution of the "blue" copper electron transfer proteins plastocyanin and azurin. (3) Structure in solution of some proteins of unknown crystal structure (stellacyanin and papaya lysozyme). (4) Studies of the structural role of aromatic amino acid residues of proteins by examining the conformation of chemically modified proteins. (5) Studies of the structure and conformational role of the carbohydrate residues of glycoproteins.